Vibratory screening machines are well known in the bulk materials handling industry. Vibratory screening machines are used particularly for the size classification of bulk particulate materials such as mineral bearing ore. Vibratory screening machines usually consist of screen decks, supported on a vibratile frame structure, operatively linked to a motorized vibratory mechanism.
Modular-type screen decks are well known, consisting typically of a matrix of screen panels, generally mounted on a number of steel runners. The steel runners are usually mounted on a steel grid or lattice-type structure, the grid forming part of the vibratile frame structure. The vibratile frame structure, together with the motorized vibratory mechanism, is normally supplied by the manufacturer, while specialist screen deck suppliers add and supply replacement parts such as the runners and the screen panels.
The screen panels and the runners wear as the classified particulate material flow across and through the screen panel apertures as well as over the runners. The known designs of the runners are such that, although the runners do not wear as fast as the screen panels, they do have to be replaced from time to time.
As the runners provide support for the screen panels, they typically extend across the whole surface of the screen. The replacement of runners therefore usually requires the removal of all the screen panels, the unbolting of the runners from the grid, and the subsequent replacement of the runners. This procedure is time consuming and labour intensive, causing substantial equipment downtime relative to the replacement of, for example, a screen panel. When downtime is planned for replacement of worn screen panels and/or runners, it typically entails production to be stopped or reduced. The wear resistance of the screen panels as well as the runners are therefore of utmost importance to reduce wear and consequential downtime of the vibratory screening machines during refurbishment, as well as the capital costs of replacing the worn runners.
It is accordingly an object of the present invention to provide a screen deck runner assembly for vibratory screening machines that overcomes or at least partially alleviates some of the disadvantages mentioned above.